1. Field of the Invention
The present invention relates to a television broadcasting system for broadcasting prerecorded video programs over cable television channels, and more particularly, to a broadcasting system which provides customer access to a large variety of prerecorded video programs in accordance with customer preferences.
2. Description of the Prior Art
Systems are known which allow subscribers to choose what video programs they would like to view on their cable television channels. For example, in one such system a transmitting station scrambles the video and audio signal so that a conventional television cannot receive the signals clearly. A decoder is provided to each subscriber to unscramble the coded signal, and the use of the decoder is recorded for billing purposes. Thus, by using the decoder the subscriber may selectively view the information made available by the cable television company. However, the subscriber has no input as to what video programs are shown and must select from those programs provided by the cable television company at any given time.
Other systems exist which allow a subscriber to specify which video program is desired for viewing at a particular time. For example, private coaxial distribution networks exist which allow a transmitting station to simultaneously transmit a plurality of unscrambled subscription television program signals to a plurality of subscribers on a plurality of television channels. Each signal is transmitted at a different frequency which corresponds to a different television reception channel, and each subscriber is provided with a switching mechanism by which the subscriber may view the desired television channel. However, such a system is disadvantageous in that substantial start-up costs are required to set up the private coaxial distribution network and to add new subscribers, thereby reducing the accessibility of the system to the general public.
Additional broadcasting systems exist which allow a subscriber to select a video program using a command terminal unit at the subscriber's home. The command terminal unit is typically a microprocessor with a key pad coupled to the telephone system and the television cable. The subscriber uses the key pad to select the desired video program with the subscriber's selection being sent over the telephone lines. In response to such a request over the telephone system, the cable company sends the video information over the cable channel in a time compressed form to only the subscriber that requested the video program. The video program is then converted to real time before it is broadcast at the subscriber's home. Such a system is disclosed in U.S. Pat. No. 4,590,516 to Abraham, U. S. Pat. No. 4,567,512 to Abraham, and U. S. Pat. No. 4,506,387 to Walter, for example.
Further systems exist whereby a subscriber may select video information using only the subscriber's telephone, thereby obviating the need for a control unit at the subscriber's home. In such a system, the subscriber dials the cable television company and enters a digital code corresponding to the selected video information. The video information is then sent via a cable in time compressed form and broadcast to the subscriber requesting the video program. Such a broadcasting system is disclosed in U.S. Pat. No. 4 521 806 to Abraham, for example. However, as in the aforementioned prior art systems, the programming requests are processed in order and are not tabulated to schedule the broadcasts in accordance with generalized viewer preferences.
In yet another broadcasting system, such as in U.S. Pat. No. 4,381,522 to Lambert, a subscriber desiring to view a particular video program enters a digital code on the subscriber's telephone, the code corresponding to the selected video information. A minicomputer at the cable station responds to the viewer selection signals provided on the telephone line and outputs the selected video information on one of a plurality of channels. The channel and the start and stop times for the selected video program are displayed on the television monitor of all subscribers to the video system, and the program is then broadcast so that any subscriber interested in the program can view it. However, each program selected is typically assigned for broadcast in the order that it is received, although certain programs may be given higher priorities, such as, for example, emergency first aid information scheduled for immediate broadcast. In any event, Lambert does not provide a subscriber voting system whereby video programs preferred by the viewers may be given priority over other video programs.
Another broadcasting system which allows for subscriber selection of video programs has been disclosed by Clark et al. in U.S. Pat. No. 4,761,684. Clark et al. therein disclose a system in which a subscriber can input a digital code using a touch tone telephone for selecting a video program for broadcast on a cable channel. At the transmitter, the subscriber's request is used to retrieve the requested video information from memory and to place it on a queue for broadcast. A telephone company's "900" service may be used for this purpose so that income can be generated for the cable television company. On the other hand, as taught by Gordon et al. in U.S. Pat. No. 4,763,191, a dial-a-view service may be used whereby a subscriber desiring to view a particular video program dials an "800" dial-a-view number for ordering that selection through the telephone network. The local cable company is accordingly instructed to display the desired program in the order requested by the subscriber. In any event, the selected video program is then displayed on a common channel of the television monitors of all subscribers.
However, since the requests in both the Clark et al. and Gordon et al. systems are placed in a queue, the first video information selected by a subscriber is the first video information broadcast on the common channel. In other words, the requested video programs are prioritized for broadcast only according to the relative time that the subscriber's requests were received. Such systems have the obvious limitations that each subscriber has no idea when a requested video program will be shown, for the broadcasting time is completely dependent upon the number of previous video requests placed in the queue. A more responsive and predictable video system is required.
The subscriber selection difficulties inherent in each of the above systems have been partially circumvented by the growing video rental market. Video rental stores provide the renter with access to a large library of video programs without a wait for the particular program to be broadcast over one of the cable channels. Hence, maximum viewer flexibility has been obtained. However, since recent releases of popular first run movies are often difficult to obtain by the video stores and even more difficult to obtain by the patrons of the video stores since all available copies of the more popular videos are often rented quickly, the patrons of the video rental stores have often lost the above-mentioned viewing flexibility. They instead must sign a waiting list and make further trips to the video rental store before obtaining the desired video program. In fact, the patrons sometimes never get to see the video program they originally requested because they either lose interest or rent another selection. Such an arrangement remains an inconvenience to the patron of the video store.
Accordingly, there is a long-felt need in the art for a television broadcasting system which will provide the subscriber with the wide video selection of a video store without the limitations of previous broadcasting systems or the procurement problems of video rental. In particular, there is a need for a television broadcasting system which is more responsive to the desires of the viewers so as to enable the viewers to have more control over their own video programming. The present invention has been designed to meet this need.